1. Field of the Invention
The present invention relates to an apparatus and method for controlling a wireless feeder network used to couple access base stations of an access network with a communications network.
2. Description of the Prior Art
Typical access networks provide a plurality of access base stations which communicate via wireless links with mobile or fixed end user equipment. A number of wireless communications protocols are known for the communications between the access base stations and the end user equipment, for example WiFi, WiMAX, or LTE wireless communications, etc.
The various access base stations need to be coupled with a communications network to allow traffic originating from the user equipment to be propagated on to the communications network, and for traffic within the communications network to be delivered to the required end user equipment within the access network. One known way to provide such connection between the communications network and the access network is to provide wired backhaul connections from each of the base stations to the communications network. However, this requires the access base stations to be located in places where it is feasible to provide a wired backhaul connection to those access base stations. As an alternative to a wired backhaul, it is also known to provide a dedicated out-of-band wireless backhaul to provide a point-to-point wireless connection between each base station and the communications network.
However, as the demands for bandwidth increase, cell splitting techniques have been used, where a cell that would have previously been serviced by a single access base station is sub-divided into smaller geographical regions served by additional access base stations, such cell splitting techniques providing a well-proven technology for increasing system capacity. However, as the number of access base stations are increased, this increases the cost of providing the earlier-described wired or wireless point-to-point backhaul connections between the various access base stations and the communications network. This significantly increases the cost to the operator. For wired backhaul, the cost clearly increases as each additional backhaul connection is required. For a wireless backhaul solution, there is a similar increase in the cost, since scarce radio frequencies must be allocated in advance, and once fixed the frequencies allocated for access (from an access base station to the mobile or fixed end user equipment and vice versa) and for the backhaul (from a base station to the network router and vice versa) cannot change.
There is a growing requirement for the access base stations to be made smaller and easier to deploy in a variety of locations. For example it would be desirable to be able to place such access base stations on street furniture such as lampposts and signage. However, to achieve such an aim, it is necessary for the access base stations to be small, compact and consume low power. There is also a need for an efficient way to connect such access base stations to the communications network via a wireless backhaul connection.
One known approach for reducing the costs associated with providing a backhaul connection for the various base stations is to employ one or more of the base stations as relay stations. Hence, in such embodiments, relay traffic can be passed between base stations, so that at least some of the base stations do not directly need to be connected to the backhaul. However, such relay traffic consumes a significant amount of the total resource provided within the access network for handling data traffic.
Accordingly, it would be desirable to provide an improved mechanism for coupling access base stations of an access network with a communications network, which allows freedom in placement of base stations of the access network, whilst providing a spectrally efficient backhaul connection.